After 15 years in this profession, and avidly studying plane crashes, it's truly painful to read these threads early on.
First off all eyewitness accounts shouldn't be posted, or posted with a massive disclaimer that they are almost certainly and wildly inaccurate
Professional note: The ground speed on the radar is an estimate calculated by the radar position server, used often with Mosaic radar, but can be less accurately ascertained by a single sourced radar
Unless they have encoding ground speed display, not likely, the ground speed is not directly indicative of the ground speed of the airplane....